High density computer equipment storage system

ABSTRACT

This relates to the manner in which computers are configured in a given area in order to conserve space and to deal with cooling issues associated with the close housing of a large number of computers. Efficient arrangements for efficiently increasing the density of computer configurations are shown, particularly when used in a network server or host environment.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent appiication Ser. No.10/279,153, filed Oct. 23, 2002, which is a continuation of U.S. patentapplication Ser. No. 09/479,824, filed Jan. 7, 2000, now U.S. Pat. No.6,496,366, which claims priority to Provisional Patent Appiication Ser.No. 60/161,578, filed Oct. 26, 1999, the disclosures of which areincorporated by reference herein in their entirety.

FIELD OF THE INVENTION

This relates to the manner in which computers are configured andprovided in a given area in order to conserve space and deal withcooling issues associated with housing a large number of computers.Aspects of the invention assist with increasing the density at whichcomputers may be provided, particularly in a network server or hostenvironment.

BACKGROUND OF THE INVENTION

Many computers today are assembled from components built to one or moreindustry standards. The use of standardized components using specificinterfaces allows for ease of supply, efficiency in production, andcompetitiveness in pricing. A further advantage associated with the useof standardized computer components, as opposed to custom pieces, isthat of performance.

The dollar-for-dollar performance advantage of many standardizedcomponents over similar custom components can be viewed as a beneficialconsequence of the balance between the resources invested in eachproduct and the efforts to optimize its function. Standardizedcomponents have higher sales volume and return potential than customcomponents, thereby generally allowing additional resources to beinvested in their production. Standardized components also face broadercompetition regarding performance. Therefore, if sales are to be made ata given price point, the performance of the corresponding standardizedcomponent must excel.

In contrast, even when custom components are desired, it is often noteconomically feasible to optimize performance. The paramount concern isto meet the specific needs calling for the customization. This isparticularly so when space conservation is the primary consideration.Although the number of smaller computers available for duty where spaceconservation is important has increased, they are typically veryexpensive. Also, these smaller custom computer systems often suffer inthe areas of computing speed and system reliability relative tocomputers using less costly standardized components.

It should be noted, however, that additional factors affect theperformance of existing space-saving computer systems. The compaction oflayout in shrinking main board sizes results in component crowding andimparts additional design constraints which hinder design for optimalperformance. Crowding can adversely affect the manner in whichcomponents are connected as well as result in significant heatdissipation problems. Further compromises are often made in shrinkingcomputer sizes. To conserve space, smaller fans or fewer fans may beincluded in a design. Also, custom-made power supplies and data drivesmay be required in producing a compact system. As with main boardsdesigned for small size, these units often lag in performance relativeto their standardized counterparts.

The use of custom components introduces further difficulties when theybreak down. Supply issues can be such a difficulty as to make it morefeasible to replace an entire machine so as not to lose its computingpower for an extended time, rather than wait for repair componentsnecessary to get the existing machine up and running. This difficulty isoften compounded by an increased failure rate experienced with customcomponents.

All of these disadvantages aside, there exists a need for compactcomputer systems in the server industry. It is this very need which hasjustified acceptance of current compact systems despite theirperformance and thermodynamic disadvantages. Especially with the adventand rise of the Internet and World Wide Web, an increasing demand formore computers to be connected to serve as network hosts or servers hasarisen.

The function of network serves may be carried out by more traditional“servers” in the form of powerful computers usually configured toperform specific functions. Another more recently developed model inproviding network services is with grouped computers or “modules”linked, in part, through software such as the VNC software packageavailable through Oracle, Inc., to form a “farm” or “puzzle” ofcomputers working together. Computers set up in a farm or otherwiseprovided in a coordinated set will include their own processors, datadrives and so-forth in order that each may accomplish a fraction of thework intended for the whole.

Farms, in particular, have several advantages over typical servers. Oneadvantage is the combined speed of processors working together in acoordinated manner. Another advantage resides in the redundancy of afarm's structure. If any one module fails, it can be extracted orreplaced with no ill effect other than the fractional loss of the farm'scapacity. Put another way, failure of part the set of computers does notshut down the whole. In contrast, when any portion of a server fails,the whole system may go down. If the failure itself does not cause theloss, shutting down the computer for a necessary repair certainly will.

Irrespective of the type of network host that might be employed, it isclear that there is a growing need for compact, serviceable networkresources. This has lead to an increasing need for space in which tohouse the network host units and a consolidation of spaces where theyare located. Sites known as co-location sites where numerous networkedcomputers find a home now exist. Space for the computers is typicallyrented at such sites. Rent calculations may be based on the overallspace occupied, power consumption and bandwidth handled by the computersoccupying the space. Because of the relationship between such factors,it will often be in favor of both a co-location site and computerservice provider to maximize both the density and performance efficiencyof the computers at a given site. By increasing the density at whichcomputers may be packed into a given area, the service provider benefitssince less space is required for a given number of computers; theco-location site benefits since the ultimate bandwidth available inassociation with the space available may be greatly increased.

Other less apparent benefits stem from conserving the space a hostcomputer occupies. In many instances, it will be economically feasibleto forestall the retirement of otherwise outdated host computers sincethe cost of the space they occupy is relatively lower, therebyjustifying their continued service for a period of time. On the otherhand, where it is preferred to only maintain the highest-end computersin service, the savings available by minimizing the size of suchcomputers without hindering performance is quite clear. There exists aneed for computer systems adapted for realizing these many advantages.

Typically, at a site where numerous computers are connected to anetwork, the computers are provided stacked in racks arranged inrepeating rows or cells. Access to the computers is necessary forservicing, upgrading hardware, loading software, attaching cables,switching power on and off, and so forth. The elimination of as muchaccess space as is feasible can increase the density of computer systemsthat may be provided for a given square footage of area at a site.Moveable rack solutions can be used to decrease access spacerequirements. However, they have not gained wide acceptance.Consequently, there exists a need to eliminate extraneous access spacewhile still maintaining the use of relatively inexpensive, standard (ormore-or-less standard) racks.

A computer rack that is currently being widely used measures roughly 19inches wide, 30 inches deep and 74 inches high. In at least oneco-location site, these racks are lined up in rows of roughly 10-30units with access doors on each side of a rack. Access aisles areprovided on both sides of the rows. Many of the racks are filled withcumbersome computers mounted on sliders which are attached throughmounting holes provided in the front and back of the rack. Regardless ofthe chassis design of the computers (or lack thereof where computers aremerely built on open trays with their components uncovered) and how theyare mounted to the racks, data devices included in the computer areaccessed from the front. Main board I/O's, other I/O's, power cords andsuch items are typically accessed from the back. It is this latterdesign aspect which not only results in inefficiency in the amount ofaccess space required, but also in the frequent inefficienciesassociated with having to administer services to both sides of acomputer. Consequently, there exists a need for computers useable in anetwork setting that are accessible and fully serviceable from a singleside.

In order to significantly increase the density at which computers in agiven space are provided, the only solution to date has been to shrinkthe computer's box. As such, there exists a need to increase the densityat which computers may be provided in a given space by what means arepossible while still having the ability to utilize standardizedcomponents. Aspects of the present invention including single-sidedaccess help in this regard.

Additionally, there exists a need for improved cooling of computers,especially where large numbers are provided. This need is compounded byincreased computer density. Features of the invention help meet thisneed as well. In certain situations, this need to maintain acceptablecomputer temperatures can compete with the need to maintain theenvironment in which the computers are housed at an acceptabletemperature without exorbitant expenditures for environmental cooling.Certain features of the invention directed at cooling the computers helpin this regard.

SUMMARY OF THE INVENTION

A system designed to maximize the density of computers that may beprovided in a given space is provided. Several features of the systemmay enable one to provide a higher density of computer systems at asite. Preferably, the computers are built from standardized orreadily-available components, except for the chassis herein described.

One way in which embodiments of the present invention conserves spaceand increases computer density is to eliminate the need for access toboth the front and back of a computer. This is accomplished by aninventive chassis design in which ports for items requiring physicalaccess are placed only at the front of the chassis. Items requiringphysical access include, but are not limited to: various data drives orstorage devices and physical input and output sockets. Preferably, therear of a computer chassis made according to the invention is free ofany such access ports. However, this “front access” feature of thepresent invention does not require that each and every physicalattachment to a computer be located in front of the machine. Desirably,those which require physical access periodically or would significantlyhinder forward removal of the machine from a rack in which it may bestacked are provided for at the front of the chassis. At least thosefeatures located on the main board which would normally be accessed frombehind and accessible data drives are provided for in the front of theinventive chassis.

The above-described chassis configuration allows for effective placementof computer components in a back-to-back arrangement within a rack orother supporting structure. This back-to-back placement of computercomponents within a rack forms a highly desirable aspect of theinvention. Such placement often doubles or further multiplies thedensity potential for rack computer systems, e.g., those in which thecomputers would otherwise be mounted one unit deep. The back-to-backmounting of computer chassis may also involve the back-to-back placementof full-function computers linked to one another or the back-to-backplacement of a computer and a device such as a drive array serving thecomputer which it abuts.

Another aspect of the invention which aids in increasing the density atwhich computers may be provided is attained by placing the inventivechassis in a back-to-back fashion in a manner so that a space betweenthe backs of the various chassis is present when the units are in arack. Cooled or forced air may then be provided in this rectangular backspace (and, if so desired, to the space between the sides of the chassisand side panels of some racks) to pass through a computer chassis and bevented through the front of the machine. Optimally, this back-to-frontflow of cooling gas traveling through the computer is directed toparticularly hot-running or temperature-sensitive components such aspower supplies or CPU's. Various inlets, vents, fans, and baffles may bespecially-configured or controlled to provide desired flow propertiesand optimize cooling and/or temperature stabilization. Ideally, forcedair at ambient temperature or forced and/or cooled air as low as about40° F. (5° C.) or lower is used. Air provided in the space betweencomputers and or the rack which house them may come either from abovethrough ductwork typically present in a building or below whereadvantage may be taken of the fact that heat rises.

The backspace and optional sidespace between the computers or rack sidesmay be used in another advantageous manner. Especially where maintaininga lower environmental temperature is a concern, a flow reversed fromthat described above will be advantageous. Such reversed flow may beaccomplished by drawing ambient air by fans and/or a partial vacuumthrough the computer chassis past heat-generating components and ventingit from the common space between the computers by a hood or plenum, ventor other means. Common ductwork may take the heated air out of the site.Alternately, it may be preferred that each hood independently exhaustsair out of the site in which the computers are located. Providingfront-to-back flow will cool computer components as well as helpmaintain lower ambient temperatures than possible with otherhigh-density network computer solutions. As desired above, it ispreferred that the flow of cooling gas is directed to or by hot-runningor temperature sensitive components.

Providing cooling flow in either a back-to-front direction or afront-to-back direction as possible with the hardware and/orconfiguration of computers and racks as disclosed herein forms part ofthe present invention. Generally, this invention includes methods andalso various hardware components either in isolation or in combinationwhere they may work together to ultimately achieve the desired results.

In accordance with embodiments of the present invention, a set ofcomputers is provided. The set comprises: at least two computers, eachcomputer comprising at least one heat-generating component, eachcomputer adapted to permit air to flow in the computer such that airflowgoes through, over, or adjacent to the at least one heat-generatingcomponent to cool the at least one heat-generating component; and a rackconfigured for the at least two computers to be placed in a back-to-backconfiguration such that the rack and computers will cooperate to directair that flows through the computers (1) up to exit the rack through anupper section of the rack, (2) down to exit the rack through a lowersection of the rack, or (3) both.

In accordance with embodiments of the present invention, a method ofcooling one or more heat-generating components in two or more computersis provided, where such computers are mounted back-to-back in a rack.The method comprises: directing air into and through each of thecomputers to cool at least one heat-generating component; and directingthe air (1) up to exit the rack through an upper section of the rack,(2) down to exit the rack through a lower section of the rack, or (3)both.

BRIEF DESCRIPTION OF THE DRAWINGS

Each of the following figures diagrammatically illustrates aspects ofthe present invention. The illustrations provide examples of theinvention described herein. It is contemplated that combinations ofaspects of specific variations or combinations of the specificvariations themselves are within the scope of this disclosure.

FIG. 1 shows a configuration of the inventive chassis as it may bebuilt-up with certain components to form a computer.

FIGS. 2A, 2B, 2C, 2D and 2E show configurations of the inventivechassis.

FIGS. 3A and 3B show back-to-back computer system configurations.

FIG. 4 shows an oblique view of a rack partially filled with computersaccording to the invention.

FIGS. 5 and 6 show partial cut-away side views of racks filled withcomputers according to the invention.

DETAILED DESCRIPTION

FIG. 1 shows a configuration of the inventive chassis as it may beassembled with standard components. Although the use of standardcomponents is preferred, of course, none of the components must be so.The chassis 2 will usually include a chassis body 4 and a chassis cover6. A main board compartment 8, and a power supply compartment 10separated by a baffle 12 are optionally provided. Preferably, the mainboard compartment 8 is sized to fit an ATX form factor main board 14.Preferred main boards include models N44BX, L44GX, 810, 810E and C440GXby Intel, Inc. Such main boards typically include an I/O shield 16. Thechassis 2, is preferably made of zinc plated mild steel sheet metal,with the front panel 18 painted. Rivets, welds or other suitablefastening methods may be used to secure various components and hold thechassis body 4 in shape.

The main board compartment 8 is preferably of a height sufficient toinclude room for a 3.5 inch disk drive 20 above main board 14 in a port22 in the front panel 18 of the front section 24 of the chassis. Thevariation shown in FIG. 1 is “2U” in height. Especially when usingdifferent CPU configurations, alternate heights as described below maybe advantageous.

Whatever the configuration, a port 26 for the main board shield 16 willbe provided in the front panel 18 of the chassis body 4. A port 28 inthe front panel for an external SCSI drive (not shown) or other suchdevice may also be provided. Another port 30 of such a size to fitnumerous connectors (such as a parallel port connector) or a port for anEthernet card (not shown) to fit in the main board 14 is also providedin the variation shown in FIG. 1. Further, ports 34 for switches areoptionally provided.

The front panel 18 defining the various ports may be configured toattach to a rack by providing interface sections 36 extending from thesides 38, 40 of the chassis body 4. In-line with the power supplycompartment 10, in the variation of FIG. 1, the front panel 18 alsoincludes a port 42 capable of receiving a 5¼ inch device 44. A number ofdevices may be optionally used in this port. As diagrammaticallypictured, a drive 44, such as a removable-medium drive (e.g., CD, DVD,ZIP, JAZZ, DAT, Smart Cards, Flash disk and Tape drives or otherswhether designed for a standard size desktop or network computer or ofsmaller size for a portable computer or the like) may variously be usedin a hard-wired, hot-swappable or replaceable configuration. Ahot-swappable hard drive or CD ROM may be preferred.

Common to all such drives is the need for access for the purpose ofchanging the data storage media or for pulling the device itself. Thesame is true for the connectors attachable to the shield 16 of the mainboard 14 discussed above and/or for connectors to accommodateUSB/external SCSI or parallel port devices or other auxiliary datadrives configured for plug-in use. In the variation shown in FIG. 1,optional port 46 accommodating a power cord fitting to a power supply 48to be housed in the power supply compartment 10 is provided.

Preferably, the chassis 2 is configured so power cords such as thosewhich would be connected at port 46 will be located at one side of theunit, while other cords, wires or the like for data transmission will beconnected at the other side. In this way, two well-organized columns ofconnection members will be developed when a rack is filled with chassis2 spanning the front of it.

Preferably, the power supply 48 for use in the assembled computer ismade of high-quality standard components. In the configuration shown inFIG. 1, a customized power supply shield 50 may be provided with a step142 from a lower region 52 to an upper region 54 in order to accept thelarger 52 inch devices. Just as the power supply shield 50 may include astep 142 to provide clearance for desirable drives in the power supplycompartment 10, the baffle 12 may include a step or jog 140. The jog 140shown is provided as clearance for both the 5¼ inch port 42 and forcertain desirable main boards 14 in the main board compartment 8 whilemaintaining a total frontal width narrow enough to fit in a typicalcomputer rack having a 19 inch wide opening.

A hard drive 56 may be placed below any 5¼ inch device used. It is alsopossible to provide various brackets elsewhere within the chassis body 4to mount additional hard drives as space permits. The placement of thehard drive 56 indicated is, however, optimal in view of the coolingfeatures provided in this variant of the invention. While vents 58, 60and 62 and fans 76 in front of the vents are provided foremost togenerate a stream of air optionally in a direction as indicated to coolthe power supply 48, the drive 56 is exposed to a beneficial stream ofcooling air as well. Vents 64 and 66 in the power supply cover 50 allowthe air to move through the same without significant impediment.

In a manner similar to that of the configuration of the power supplycompartment 10 which is intended to pass cooling gas or air across thepower supply, vents 68, 70 and 72 and fans 76 in front of the ventsprovided in the main board compartment 8 direct cooling air over or nearthe CPU(s) 74 of the main board 14. In the variant pictured, a diagonalflow of air may be achieved as indicated.

The cooling of the chassis compartments 8 and 10 may be provided by fans76 which severally run continuously while the computer is on oralternatively there may be more selective control of at least some ofthe fans 76. For instance, where a thermal control unit 78 is includedin the computer design, separate channels of the unit may be set tomonitor the temperature of the chambers and turn on and off fans in eachof the chassis compartment or the device itself to help maintaintemperatures as constant as possible. Such a set-up can reduce thermalcycling issues that may arise due to differing power consumption andwaste-heat generation of components (especially CPUs) depending on theirusage. Also, the direction of air flow may be varied by switching thedirection in which the fans 76 turn.

FIG. 2A shows the variation of the inventive chassis which is shownbuilt-up in FIG. 1, as may any of the other chassis pictured and/ordescribed. The chassis of FIGS. 2B , 2C, 2D and 2E include ports withgenerally identical functions as indicated by corresponding sizing,profile and/or numbering. The differences between the chassis are amatter of what ports are considered to be preferred for the computerconfiguration desired. All configurations, however, exhibit the commonfeature that each of their ports for all components requiring ordesigned for intermittent access by a user are on one side of thechassis. In the variant shown in FIG. 2C, no jog in the baffle 12 isrequired since no 5¼ inch device port is provided.

In the variant shown in FIG. 2D, no baffle is included at all. Toaccount for the loss of such support as provided by a baffle 12 in theother variants of the invention, a top flange 132 is preferably providedaround the entire periphery of the chassis body 4. Further, as shown inFIG. 2D, the chassis body 4 need not include any ports for internal datadrives. As alluded to above, it is possible to use the chassis incombination with external data devices configured for intermittentconnection. Dedicated ports in the face 18 may be provided for suchaccessibility. Alternately, optional ports 144 provided for a main boardI/O's ports may suffice.

FIGS. 2D and 2F show a “1U” variant of the inventive chassis. Such aconfiguration may be used to efficiently house a 810X main board. Thestacking of 1U chassis in a computer rack enables the provision of up tofour times the number of computers as compared to others (such asRack-Mount 02 systems available through Silicon Graphics, Inc.) that maybe provided in a given computer rack. Therefore, up to 84 IU computersmay be housed in a 74 inch high standard computer rack.

A 1 U chassis will be particularly advantageous to use where additionalCPU power is desired for a farm or set of computers in a computer racksince use of such a slim chassis will result in packing more processorpower into less space in a computer rack. However, fewer peripherals maybe used in such a slim design. Also, presently, typical two CPU mainboards may not be used in a 1 U chassis. In view of such limitations inassembling a rack of computers, it will often be advantageous to employcomputers built in chassis of varying heights. Still as long as asufficient number of 1 U chassis are employed in combination with tallerunits, it is possible to provide computer racks with upwards of 40 or 60computers for a 74 inch high computer rack.

By virtue of each chassis being configured to accept a main board 14 ina horizontal orientation and the remaining layout of the chassis adaptedto accept other components beside the same (whether on the opposite sideof a baffle wall 12 or not), it is possible to maintain the low profilesdisplayed such as with 1 U and 2U designs specifically described. Thisconfiguration is also useful for producing low profile computers ofheights anywhere between about 1 U and about 3U that fit into a standardcomputer rack.

The approximate height of a 1 U chassis is about 1¾. Naturally, thevarious 2U, 3U, 4U and taller models have heights corresponding tomultiples of the 1 U height. As clearly known in the art, a 1 U chassisunit is mountable between three mounting holes on a standard computerrack. Taller units span an increasing number of holes.

As with the other chassis in FIGS. 2A-2C, the variations shown in FIG.2D may be mounted on the rack by its front flange members at interfacesection 36. Due to the height of the chassis, the number or width ofvents 80 and 84 may be increased as shown to maximize the opencross-sectional area for cooling gas to pass through a chassis.Additional, but smaller, fans may also be employed. Also, it may beadvantageous to use smaller data drives in such a chassis, e.g. drivesmade for laptop or portable computers, or to eliminate provision forinternal drives and rely only on ports for external drives as describedabove.

Especially with the unmodified flange-mount chassis designs shown inFIGS. 2A-2D, where longer chassis are desired for use in a back-to-backconfiguration in a standard rack, it will be preferred to mount thecomputers to racks using longer bolts (or other affixation means) andwith spacers 112 between the interface section 36 and opposing rackportions 114 across from each on a rack as indicated in FIG. 4. Aspictured in FIG. 2D, integrated bolts 134 of a style pressed in to thechassis body 4 so they will remain with the unit and serve as handles toremove the chassis may be generally preferable with any chasis foraffixing the chassis 2 to the rack 98 along each side 114. Spacer 112may be the height of only a single chassis, of the rack mountingportions 114 or somewhere in between. In this way, it will be possibleto produce longer chassis and still maintain the advantageous backspace106 as otherwise possible such as described below.

The goal of providing longer chassis for use with a standard rack can beaccomplished with the inventive chassis in other manners. As shown inFIG. 2E, brackets 116 attachable to the chassis itself that may be setback or offset from the face 18 of the unit in order to provide achassis position which is pushed forward from the norm. Here brackets116 are provided with holes 118 with which to mount the chassis to therack sides 114. Depending on the depth of offset 120 of each bracket116, or how far back the brackets 116 are located on the chassis body 4,it is possible to advance the front of the chassis a significant amountout the front of the rack so as to be able to provide a lengthy chassiswhich may still be mounted back-to-back with other chassis (of similaror different configuration) as described herein.

Yet another manner to accomplish the same goal is to provide an integralflange or interface section 36 configured like that of the bracket 116so it provides an area for attachment set back from the face 18 of thechassis. Such an interface section 36 will provide the desired forwardoffset 120 to enable back-to-back placement of longer chassis thanotherwise possible in a standard rack without the use of spacers 112 orthe like.

Another advantageous feature that may be utilized in the presentinvention to include a face plate 122 for use with the chassis. Such aface plate 122 as shown in FIG. 2E may be used with any variation of theinvention. The face plate 122 will typically include ventilation holes124 to allow cooling air or other gas to pass through. In a preferredvariation, the ventilation holes span most of the face of the piece.Optimally, the face plate 122 is connected to the chassis by a hingedinterface. However, any slip fit, friction fit or snap fit to the frontof the chassis will suffice. At least one side of the face plate will beleft open so that cables, wires and like connected to the front of acomputer assembled according to the present invention can be routed outthe open area(s) to connect to such components as required for thecomputer to serve in a network. Preferably, both sides are open toaccommodate the dual wire/cable column configuration for power and datacables, respectively, as discussed above.

While any of the variations of the chassis described herein may make useof the face plate 122, only higher-end models will use a separate bezel126. In this variation of the invention (and in like variations ofdiffering height vent configuration, baffle configuration, etc.), thebezel 126, once connected, forms part of the chassis body 4. In thevariation shown, one or more common fasteners attach each bracket 116and the bezel 126 to the sides 128 of the chassis body 4.

An advantage of using such a bezel 126 is that it may be customizedeasily or exchanged for another which is more advantageous for a givencomputer to be built. In essence, the bezel 126 allows for increaseddesign and marketing flexibility since changes in chassis 2configuration can be made in a piecemeal fashion. This differs fromthose variations of the chassis which include an integrally-producedfront panel 18.

Regardless of such variations as possible, a preferred commonalitybetween all the configurations of the chassis 2 is the general placementof vents. While some differences are shown between the chassis shown inFIGS. 2A-2E, at least one set of vents 80 is provided in the rearsection 82 of the chassis body 4 and another set 84 in the front section24. Depending on the placement and selection of components with which tobuild a computer in the inventive chassis 2, the placement of the ventsin the rear on the back panel 86 or side panels 38 or 40 may be varied.However, for those aspects of the invention in which venting and theflow of air through the chassis is relevant, some vents will be providedin the front 18 of the chassis 2. Even when not used with other aspectsof the present invention, the air flow may travel from the rear section82 to the front section 24. Alternately, it may travel in the otherdirection. In fact, direction of air flow may be set depending on thedesired effect on the environment and/or condition(s) of theenvironment. It may even be switchable to account for changingenvironmental conditions such as variations in the temperature of thesite housing the computers due to seasonal climate or the difference inenvironmental temperatures between day and night or other events.

The advantageous use of air flow through the entire chassis and acrossheat-generating components is still possible where only one compartmentis provided within the chassis 2. While the baffle 12 is oftenadvantageous for isolating compartments for placement of hot-runningcomponents and aiding the vents in directing air flow, its use is merelyoptional. Especially in instances where a removable power supply isprovided in a port such as port 42 in the front of the chassis, theadvantages of a two-compartment chassis design wanes.

FIG. 3A shows an example of an arrangement in which use of a removable,power supply would be particularly advantageous. In this variation ofthe invention, a computer module 88 is built in accordance with thatshown and described in FIG. 3B utilizing a chassis with front access forcomponents, except a redundant two-socket power module (not shown) isprovided. Placed at the back of unit 88 is an “array” or “RAID” module90 including a number of data drives 44. Together the modules 88 and 90form a powerful system 92 optimized for space and accessibility.

In such a configuration, the computer module 88 need not include a harddrive. In the array module 90, any number or type of drive(s), includingthose discussed above may be provided in either hard-wired or swappableconfigurations. Drives which require accessibility when the modules 88and 90 are mounted back-to-back are accommodated by ports in the array90 chassis on the outwardly-facing side. In this specialized variationof the invention, a port for a connector 94, such as a SCSI interface,is provided in the rear of each unit 88 and 90. Optimally, connectorports 136 and 138 will be at the bottom of each piece so units ofdiffering height may still interface with one another.

A more typical application of the inventive chassis is shown in FIG. 3B.Here, full computers 96 built with the chassis 2 are provided in aback-to-back configuration. Preferably they are hooked up in the mannerof a farm. Generally, no connections will run between the units as withthe computer system 92 discussed above. This is, however, possible. Itwill be advantageous particularly where power is shared over aninterface 94 between computers 96 in FIG. 3A. This enables swapping outa removable power supply such as that which may be provided in port 42while maintaining power to each computer 96.

It is preferred that back-to-back pairs of computers 96 (whetherconnected or not) are mounted in a standard rack 98 in one layer afteranother as shown in FIG. 4. They may be mounted to the rack on slides(not shown), by integral interface sections 36 brackets 116 asalternately described above or otherwise. When no slide is used, it ispreferred to place strips of adhesive TEFLON tape 100 or the like on thesurface of at least one computer under or above another. While thechassis 2 are sufficiently strong and the assembled units light enoughto be self-supporting when bolted into a rack, the tape 100 takes upspace to provide support and makes sliding a unit out from a rack forservice more convenient.

The computer rack shown in FIG. 4 will hold up to 40 computers 96 builtwith the 2U inventive chassis. As alluded to above, this is because theuse of the chassisin a back-to-back configuration permits the doublingof the number of computers that may be stored in a standard computerrack. Of course, when utilizing chassis according to the presentinvention of different heights, this ratio changes. To do this, (unlessusing spacers 112 or offset mounting brackets 116 or interface portions36), regardless of the height of the chassis 2 the depth of the chassis102 must be less than half the available depth 104 of the computer rackin order to stack computers two deep. Without the use of specializedmounting configurations, preferably the chassis depth 102 is less than15 inches (38 cm) when configured for a 30 inch (76 cm) deep rack.

In a most preferred variation of the invention, the depth of the chassis2 is even less. For use in a standard 30 inch deep rack, the chassisdepth 102 is 13.5 to 14.5 inches deep (34 to 37 cm). This is so becausewhen a sufficient number of computers are placed back-to-back in a rackas contemplated in the present invention, an advantageous optional backspace 106 between about 1 to 6 inches, preferably about 1 to 3 inches isformed behind the computers. When side panels 108 are provided on therack 98, the back space 106 is complemented by side space 110 betweenthe sides of the computers 38, 40 and the rack side panels 108 to forman H-shaped space. The space behind the computers may, however, becordoned off to leave only a rectangular volume if desired.

When back-connected units such as array modules 90 and computer modules88 or 96 are used in combination in a rack 108, they are also preferablyconfigured in this manner to define (preferably with other computers, ofone height or another, as described in the present invention) suchchannels or spaces. The back-to-back connection between the units willnot significantly hinder the functionality provided by the air space.However, it is highly undesirable to have the air space cluttered byother structure such as cables, cords and the like. This is why thefront-access configurations of the inventive chassis are advantageouslyused in conjunction with providing an air space between computer moduleswithin a rack 98 or other enclosure as might be used.

As mentioned above, the space provided between computer modules may beadvantageously used in a number of ways. For instance, as illustrated inFIG. 5 a positive airflow as optionally indicated from above, below orin both directions, may be provided to the space. Providing a measure ofgas pressure will tend to force air through vents 80 in the unitsdefining the space as indicated. If enough pressure is provided, itwould be possible, in principle, to provide computers without fans.

However, the primary intent in providing air under pressure to the backspace 106 and/or side space 110 is to assist the fans or to provide ameasure of redundancy so that if one or more fans fail that the airpressure maintains some level of flow within the computer chassis. Sucha backup can provide a technician the time cushion needed before asystem overheats (in order to take the computer off-line or out of thenetwork or farm for repairs) before vital componentry is burnt up.

Even where forced air is not provided, the air mass may be cooled. Bydrawing cooled air through the individual computers past hot-runningcomponents, improved cooling will result. Most preferably, however,forced and cooled air, such as standard air conditioning (HVAC) isprovided with a compounding of benefits resulting.

Another benefit of providing a controlled flow of air in the back space106 and/or side space 110 to pass through the computers and be ventedout the front as indicated in FIG. 5 is the opportunity to providefiltered air to the air intakes of the computers. This will control theaccumulation of harmful dust in the machines. Additionally, lower powerconsumption costs may result for a site housing many computers utilizingthe cooling features of the invention. Efficient application of cooledair to power-intensive components is possible with the advantages ofthis aspect of the present invention.

It is noted that the cooling features of the present invention discussedabove should do still more than save energy and space to benefit thebottom line for the parties making use of them. It should also providewelcome relief for those who work at a co-location site that hasfully-adopted the new form factor offered by the present invention sinceit will not be necessary to keep the entire environment at frigid levelsin order to keep the computers present within running acceptably.

Sometimes, however, it will be preferable to reverse the airflow fromthe back-to-front airflow as variously shown in FIG. 5 to front-to-backairflow as variously shown in FIG. 6. As such, air travels from theenvironment, through the front of the computers, into the backspace 106and/or sidespace 110 and out of the rack 98. A vent in the form of ahood enclosure or plenum 130 optionally including fan(s) 146 may beprovided to exhaust air heated by components within the computer to theexterior of the site at which the computers are located via ductwork orindependently. Irrespective of its structure, in this variation of theinvention, the vent 130 may be passive or utilize a partial vacuumgenerated by a fan or by some other means. Preferably, the air isexhausted from inside the rack 98 in an upward direction to takeadvantage of the buoyancy exhibited by heated air. It is, however,possible to vent the air from below or from above and belowsimultaneously.

When higher velocities of air are reached within the channel formedbetween the components placed back-to-back within the rack 98, a ventureeffect will increasingly assist in drawing air through the machines fromthe environment in which they are housed. This effect may be bestaccomplished by top and bottom venting of the rack.

Reasons for providing sets of computers utilizing front-to-back airflowinto and out of the common space 106 and/or 110 include, but are notlimited to, maintaining an acceptable overall temperature of theenvironment in which the computers are housed, controlling environmentalcooling or air-conditioning costs and providing a self-contained unitthat may be individually vented so as to avoid contribution to anoverall heating problem of a facility or exacerbating heating problemsof nearby, less-robust systems by blowing hot air in their direction. Toaid in providing a discrete system which will not contribute to overallheating problems at a site, further isolation of the system may beaccomplished by providing insulation at, along or within the sides ofthe rack 98 and/or at any optional door(s) provided.

As similarly possible with the present invention when set up forback-to-front cooling flow, with front-to-back cooling flow the effectof loss of fan(s) in a computer may be minimized. Provision of partialvacuum within backspace 106 and/or sidespace 110 will insure a continueddraw of air into a computer if fans fail, thereby providing a measure ofredundancy; it will also generally assist the fans in providing air flowthrough the chassis 2 when everything is working properly.

Regardless of which flow direction is chosen (or if there is switchingbetween the flow directions), advantageous flow across heat-generatingcomponents which must be cooled is possible with the present invention.Generating directional flow of cooling gas through the computer chassisfrom one side to another according to the present invention avoidsrecirculation or cavitation of already heated air that hinders coolingas typically occurs with other computers

Further details as to the use or other aspects of the system describedherein may be drawn from the background that is intended to form part ofthe present invention. It is noted that this invention has beendescribed and specific examples or variations of the invention have beenportrayed. The use of those specific examples is not intended to limitthe invention in any way. Additionally, to the extent that there arevariations of the invention which are within the spirit of thedisclosure and are equivalent to features found in the claims, it is theintent that the claims cover those variations as well. All equivalentsare considered to be within the scope of the claimed invention, eventhose which may not have been set forth herein merely for the sake ofrelative brevity. Also, the various aspects of the invention describedherein, in any manner, may be modified and/or used in combination withsuch other aspects also described to be part of the invention eitherexplicitly, implicitly or inherently in order to form variationsconsidered to be part of the invention.

We claim as our invention:
 1. A set of computers comprising: a computerrack; and at least two computers, each computer comprising at least oneheat-generating component, the at least two computers placed in thecomputer rack in a back-to-back configuration, wherein: each of the atleast two computers have a depth of less than half of the depth of thecomputer rack, each of the at least two computers having a widthcorresponding to the standard U width of the computer rack, air flowsthrough each computer such that airflow goes over the at least oneheat-generating component, and the computer rack and computers directthe airflow through the computers up to exit the computer rack throughan upper section of the computer rack.
 2. The set of computers of claim1, wherein each computer further comprises a chassis comprising a frontpanel.
 3. The set of computers of claim 1, wherein each computer furthercomprises a chassis comprising enclosing at least one main board.
 4. Theset of computers of claim ,1 wherein the computers and the computer rackcooperate to define a space between at least two back-to-back computers.5. The set of computers of claim 3, wherein the computers and thecomputer rack cooperate to define a space between at least twoback-to-back computers.
 6. The set of computers of claim 3, wherein thecomputers are configured with at least one vent.
 7. The set of computersof claim 6, wherein the at least one vent is provided at a back sectionof at least one of the computers.
 8. The set of computers of claim 6,wherein the at least one vent is provided at a front section of at leastone of the computers.
 9. A set of computers, comprising: a computerrack; and at least two computers, each computer comprising at least oneheat-generating component, the at least two computers placed aback-to-back in the computer rack wherein: each of the at least twocomputers having a depth of less than half of the depth of the computerrack, each of the at least two computers having a width corresponding tothe standard U width of the computer rack, air flows through eachcomputer such that airflow goes over the at least one heat-generatingcomponent, and the computer rack and computers direct air such that theair flows up to enter the computer rack through a lower section of thecomputer rack, and exits through the computers.
 10. The set of computersof claim 9, wherein each computer further comprises a chassis comprisinga front panel.
 11. The set of computers of claim 9, wherein eachcomputer further comprises a chassis enclosing at least one main board.12. The set of computers of claim 9, wherein the computers and thecomputer rack cooperate to define a space between at least twoback-to-back computers.
 13. The set of computers of claim 11, whereinthe computers and the computer rack cooperate to define a space betweenat least two back-to-back computers.
 14. The set of computers of claim11, wherein the computers are configured with at least one vent.
 15. Theset of computers of claim 14, wherein the at least one vent is providedat a back section of at least one of the computers.
 16. The set ofcomputers of claim 14, wherein the at least one vent is provided at afront section of at least one of the computers.
 17. A set of computers,comprising: a computer rack; and at least two computers, each computercomprising at least one heat-generating component, wherein the computersare positioned in the computer rack in a back-to-back configuration,wherein: each of the at least two computers having a depth of less thanhalf of the depth of the computer rack, each of the at least twocomputers having a width corresponding to the standard U width of thecomputer rack, air flows through each computer such that airflow goesover the at least one heat-generating component, and the computer rackand computers direct the airflow that flows through the computers up toexit the computer rack through an upper section of the computer rack.18. The set of computers of claim 17, wherein each computer furthercomprises a chassis comprising a front panel.
 19. The set of computersof claim 17, wherein each computer further comprises a chassis enclosingat least one main board.
 20. The set of computers of claim 17, whereinthe computers and the computer rack cooperate to define a space betweenat least two back-to-back computers.
 21. The set of computers of claim19, wherein the computers and the computer rack cooperate to define aspace between at least two back-to-back computers.
 22. The set ofcomputers of claim 19, wherein the computers are configured with atleast one vent.
 23. The set of computers of claim 22, wherein the atleast one vent is provided at a back section of at least one of thecomputers.
 24. The set of computers of claim 22, wherein the at leastone vent is provided at a front section of at least one of thecomputers.
 25. A set of computers, comprising: a computer rack; and atleast two computers, each computer comprising at least oneheat-generating component; wherein the computers are positioned in thecomputer rack in a back-to-back configuration, wherein: each of the atleast two computers having a depth of less than half of the depth of thecomputer rack, each of the at least two computers having a widthcorresponding to the standard U width of the computer rack, air flowsthrough each computer such that airflow goes over the at least oneheat-generating component, and the computer rack and computers cooperateto direct air up to enter the computer rack through a lower section ofthe computer rack and exits through the computers.
 26. The set ofcomputers of claim 25, wherein each computer further comprises a chassiscomprising a front panel.
 27. The set of computers of claim 25, whereineach computer further comprises a chassis enclosing at least one mainboard.
 28. The set of computers of claim 25, wherein the computers andthe computer rack cooperate to define a space between at least twoback-to-back computers.
 29. The set of computers of claim 27, whereinthe computers and the computer rack cooperate to define a space betweenat least two back-to-back computers.
 30. The set of computers of claim27, wherein the computers are configured with at least one vent.
 31. Theset of computers of claim 30, wherein the at least one vent is providedat a back section of at least one of the computers.
 32. The set ofcomputers of claim 30, wherein the at least one vent is provided at afront section of at least one of the computers.
 33. A method of coolingone or more heat-generating components in two or more computers, wheresuch computers are mounted back-to-back in a computer rack, the methodcomprising: directing air into and through each of the computers to coolat least one heat-generating component; and directing the air up to exitthe computer rack through an upper section of the computer rack, whereineach of the two or more computers having a depth of less than half ofthe depth of the computer rack, and wherein each of the two or morecomputers having a width corresponding to the standard U width of thecomputer rack.
 34. The method of claim 33 further comprising the step ofproviding the back-to back computers to form in cooperation with thecomputer rack a space between the back-to-back computers.
 35. The methodof claim 34 further comprising the step of providing fans in thecomputers, the fans adapted to draw air from the computers into thespace between the computers.
 36. The method of claim 35 furthercomprising the step of providing fans in the computers, the fans adaptedto pass air through, over, or adjacent to the at least oneheat-generating component and into the space between the computers. 37.The method of claim 34 wherein the step of directing air into andthrough each of the computers comprises providing forced air to thecomputers.
 38. The method of claim 34 wherein the step of directing airinto and through each of the computers comprises providing airconditioned air to the computers.
 39. The method of claim 34 wherein thestep of directing air into and through each of the computers comprisesdrawing air to cool the at least one heat-generating component in fromthe environment and exhausting the air out the computer rack.
 40. Themethod of claim 33, wherein the one or more heat-generating componentsare provided on one or more main boards of the computers, where each ofthe computers has a front section and a back section.
 41. The method ofclaim 33, wherein the one or more heat-generating components comprisepower supplies.
 42. A method of cooling one or more heat-generatingcomponents in two or more computers, where such computers are mountedback-to-back in a computer rack, the method comprising: directing air tocool the one or more heat-generating components up to enter the computerrack through a lower section of the computer rack; and directing the airthrough the computers such that the air flows over the at least oneheat-generating component, wherein each of the two or more computershave a depth of less than half of the depth of the computer rack, andwherein each of the two or more computers having a width correspondingto the standard U width of the computer rack.
 43. The method of claim42, further comprising the step of providing the back-to back computersto form in cooperation with the computer rack a space between theback-to-back computers.
 44. The method of claim 43, further comprisingthe step of providing fans in the computers, the fans adapted to drawair from the space between the computers to cool the at least oneheat-generating component.
 45. The method of claim 44, furthercomprising the step of providing fans in the computers, the fans adaptedto pass air from the space between the computers and through, over, oradjacent to the at least one heat-generating component.
 46. The methodof claim 43, wherein the step of directing air to cool the one or moreheat-generating components comprises providing forced air to the space.47. The method of claim 43, wherein the step of directing air to coolthe one or more heat-generating components comprises providing airconditioned air to the space.
 48. The method of claim 43, wherein thestep of directing air to cool the one or more heat-generating componentscomprises drawing air to cool the at least one heat-generating componentin from the environment and exhausting the air out the computer rack.49. The method of claim 42, wherein the one or more heat-generatingcomponents are provided on one or more main boards of the computers,where each of the computers has a front section and a back section. 50.The method of claim 42, wherein the one or more heat-generatingcomponents comprise power supplies.
 51. A set of computers, comprising:at least two computers, each computer comprising at least oneheat-generating component; and a computer rack receiving the at leasttwo computers in a back-to-back configuration, wherein air is permittedto flow through each computer such that airflow goes over the at leastone heat-generating component such that the airflow flows through theback-to-back computers and the computer rack, wherein each of the atleast two computers having a depth of less than half of the depth of thecomputer rack, and wherein each of the at least two computers having awidth corresponding to the standard U width of the computer rack. 52.The set of claim 1, wherein the computer rack and computers direct theairflow through the computers down to exit the computer rack through alower section of the computer rack.
 53. The set of claim 9, wherein thecomputer rack and computers direct air to flow down to enter thecomputer rack through an upper section of the computer rack and exitthrough the computers.
 54. The set of claim 17, wherein the computerrack and computers direct the airflow that flows through the computersdown to exit the computer rack through a lower section of the computerrack.
 55. The set of claim 25, wherein the computer rack and computerscooperate to direct down to enter the computer rack through an uppersection of the computer rack and exit through the computers.
 56. Themethod of claim 33, directing the air down to exit the computer rackthrough a lower section of the computer rack.
 57. The method of claim42, further comprising directing air to cool the one or moreheat-generating components down to enter the computer rack through anupper section of the computer rack.